Adaptive Forward-Looking Behaviour in Epidemic Spreading

The course of an epidemic can be altered by changes in human behaviour. Epidemic models try to capture this aspect in various ways. We focus on a class of behavioural change models that is often referred to as “economic” or "epi-economic" in which the population is composed of forward-looking, rational individuals that adapt their behaviour to current epidemic conditions seeking to balance the benefits of social activity with the risk of infection. We show that under certain conditions it is possible to find an analytical expression for the optimal social activity as a function of prevalence. We also extend the model beyond the homogeneous mixing hypothesis, showing that it can be applied to contact networks with heterogeneous degree distributions such as scale-free networks. Finally, we compare the effects of behaviour change in "annealed" and "quenched" settings, finding that behaviour change based on local prevalence has a stronger effect on epidemic spreading than the one based on global prevalence.